The purpose of this acquisition is to conduct a randomized controlled clinical trial to evaluate a new antenatal care model. NICHD will provide support for carrying-out a Protocol developed by the World health Organization (WHO) entitled "A Randomized Control led Trial for the Evaluation of a New Antenatal Care Model" at one of the sites selected by WHO. WHO will act as a coordinator of this efEort and will subcontract with the Centro Rosarino de Estudios Perinatales (CREP) in Rosario, Argentina where the clinical trial will be performed. The specific responsibilities of CREP will be to conduct a randomized controlled trial comparing two models of antenatal care; establish the relative merits of each model; test whether the new model is as effective as the traditional multi-visit model; and provide the data from the study for analyses.